The viscosities of liquid dairy foods were measured in a slit rheometer with gap spacings as small as 34 μm. Large positive deviations from the true flow curve and an approach to a constant stress were observed below a critical rate in each material studied. This behavior is indicative of probable agglomeration and ‘‘bridging,’’ most likely in the entrance to the dye. In all cases mean particle sizes were an order of magnitude smaller than the slit.